I. Technical Field
The invention relates to a sport-technical layer for use in an artificial lawn system, in particular, intended for sports fields, which artificial lawn system is built up at least of a substrate to which artificial grass fibres are attached as well as the sport-technical layer extending under the substrate, which sport-technical layer comprises at least one damping sublayer made of a synthetic foam, which damping sublayer made of a synthetic foam is built up of an essentially rigid flat plate, which plate is provided with flatness-enhancing means.
The invention further relates to an artificial lawn system comprising such a sport-technical layer.
II. Description of the Related Art
At present, plastics are used for all kinds of different purposes, in particular the use of all kinds of plastics in artificial lawns for sports fields has developed strongly. The development of artificial grass fibres and artificial grass sports fields derived therefrom has progressed to such an extent that it is now possible to construct artificial grass sports fields which are hardly distinguishable from natural grass sports fields as regards their appearance but in particular as regards their playing characteristics.
The last few years research has been focused in particular on the development of artificial grass fibres for use in artificial lawns for sports fields, taking into account the fact that each individual sport has its own specific requirements as regards the subsoil and the surface properties.
Also in the development of new aspects of the sport-technical layer as used in an artificial lawn system the focus has been on the materials that are used. It should be taken into account in that regard that the sport-technical layer must in principle exhibit a sufficient degree of damping or resilience, so that on the one hand the characteristics of a natural lawn system are imitated as much as possible for the user, whilst on the other hand this must not adversely affect the playing characteristics, whilst furthermore the risk of injuries and the like must be prevented as much as possible. Problems that are currently experienced in the present artificial lawn systems, and in particular the sport-technical layer, inter alia concern the construction and maintenance of such an artificial lawn system. In the existing artificial lawn systems, the sport-technical layer is generally built up of a large number of plates, which are arranged in abutting relationship on a foundation layer. It has been found, however, that due to factors such as the action of sunlight but also the occurrence of temperature differences between the bottom side and the upper side of the layer as well as factors such as the dimensions and the water balance, the existing plates intended for use as a sport-technical layer are not dimensionally stable but are highly susceptible to warping and omnilateral expansion, as a result of which the connection between the plates and the functionality of the sport-technical layer is lost.
Thus, the overall connection between the various plates can no longer be guaranteed and the further construction of the artificial lawn system will be difficult if not altogether impossible because the individual plates are warped and overlap one another.